`ContractLedger` is the contract counterpart of `WasmLedger`: a real
genesis ledger with a real `ContractHostFunctionsImpl` over it, built the
way `ContractCall::doApply` builds one. It carries no test framework, for
the reason `WasmLedger` carries none — the benchmarks need a ledger and a
host, not GTest's lifecycle — so it joins `xrpl.testkit.wasm`.
`ContractHost` owns the four things the host borrows, in the order it
needs them, and its `finalize()` does what the transactor does once a
contract returns: write the data cache and the events to the ledger, then
apply. Applying alone is not enough, because `ApplyContext` reaches a
sandbox rather than the ledger under it, so `finalize()` commits that too.
`ContractHostFixture` adds the framework and the value constructors a
data test compares against, including `valueWire`, which produces the
bytes a guest writes for a value: the inverse of what `HostContext`
decodes.
`WasmLedger::tracingJournal` is extracted so a derived fixture can build
a tracing host over the same sink.
The 15 smart-contract host functions were registered through
`HostFuncWrapper.cpp` and `createWasmImport`, both of which upstream
deleted. They are now declared where every other host function is: one
`host_functions!` entry each in `crates/xrpl-host-functions`, which
generates the trait, the spec table and the wasmi registration, with a
body in the engine, a crossing in the cxx bridge, and a `HostContext`
method lowering it onto the wire.
They share the `host_lib` namespace with the escrow functions, whose host
leaves them `Unimplemented`. Wire order and gas are unchanged, so a guest
built against the old ABI still links, with two exceptions.
`emit_built_txn` and `emit_txn` gain an output region and write the TER
there as four little-endian bytes, returning the length. Their old
signature returned the TER as the call's result, which the engine reads
as a `HostError` when negative: every `tem`, `tef`, `ter` and `tel` code
would have stopped the run instead of reaching the contract.
`HostContext` decodes what the old wrappers decoded: the account region,
the typed value a `set_data_*` call carries, the serialized transaction
and the serialized event. A guest that writes those bytes wrongly gets
`InvalidParams`, so the deserializers' exceptions are caught at the call
rather than by `guarded`, which would report a node fault.
Every Rust site that enumerates the ABI is extended: the two literal
tables in `generated_abi.rs`, the import list and arity check in
`preflight.rs`, the per-function wasm in `budgets.rs`, and the three fake
hosts. `MockHostFunctions` gains the 15 methods and the matchers a
contract expectation needs.
Two `host_calls` tests cover the shapes that are new here: a typed value
decoded on its way to the host, and a TER crossing as bytes, including
the negative code that motivated the change.
Upstream rewrote the wasm VM and host-function system (Rust `crates/`
bridged via cxx), collapsed `transactions.macro` onto `TxSettings`, and
moved invariant running from `ApplyContext` to `Transactor`. This merge
resolves those conflicts and the breaks that carried no conflict marker.
Conflict resolutions of note:
- transactions.macro: took upstream's 5-argument `TxSettings` form and
re-expressed our `emitable` column as `TxSettings::emittance`, a new
scoped `Emittance` enum in TxSettings.h. `Emitable.cpp` and the
transaction code generator read the new member.
- sfields.macro: upstream claimed UINT32 75-80, so `sfParameterFlag`
moves from 80 to 86. The amendment is not live, so no wire break.
- HostFunc.h: took upstream's version, which drops `floatRoot`, and
re-added the 15 contract virtuals. `setDataNestedObjectField`'s
parameters are renamed to `(account, key, nestedKey, value)` to match
the implementation; the wire order is unchanged.
- WasmCommon.h: `SubmitTxnFailure` (-21) and `InvalidState` (-22) join
upstream's enum and the Rust `host_errors!` table. `Success` is gone;
the helpers that compared against it now return `expected<void, ...>`.
- Transactor.cpp: kept the emitted-transaction pass, now using
`checkInvariants(result, fee, InvariantScope::ProtocolOnly)`.
Breaks with no conflict marker:
- `Emitable.cpp` used the 8-argument TRANSACTION macro.
- `STTx::getSeqValue` is gone; use `getSeqProxy().value()`.
- `NetworkOPsImp::subLock_` is now `streamLock_`, held with `scoped_lock`.
- The `LedgerEntryHelpers` namespace is now `ledger_entry_helpers`.
- `keylet::vault` takes a `SeqProxy`. The three contract `ledger_entry`
parsers were copy-pasted from the vault one and returned vault keylets;
they now build contract, contract source and contract data keylets from
their own fields. `contract_hash` is added to jss.
The 15 contract host functions still register through the deleted C++
wrapper layer, so contract bytecode does not run yet. Porting them to the
Rust-declared ABI is the next commit.
